This invention relates to an automatic postal-code-number reading system wherein a postal code number on a mail item such as postcards and envelopes is automatically detected and read out.
In order to sort mail by an automatic mail handling system, a postal code number system has been adopted. The postal code numbers are written along with the address on the mail items. As stated in an article titled "Recognition of the Postal Code Number" published in the Nippon Electric Technical Journal, No. 94 August 1969, pp 30-38, the position of the postal code numbers on the mail items should be strictly determined. This may be accomplished, for example, by printing in advance on the mail items entry frames to enter the postal code numbers therein. In the case of bulk mail items such as advertizing mail, a rectangular space for the postal code numbers is strictly determined. Such rectangular space is, for example, 15 mm high and 40 mm wide, with its left lower corner being 40 mm apart from both the left edge and the bottom.
To sort such mail items, various kinds of automatic postal-code-number reading systems have been proposed. One of them is described in an article titled "Automatic OCR-Sorter" published on pages 39- 46 of the aforementioned publication. In this conventional system, only the predetermined area (such as the entry frames) on a mail item is scanned by scanning means such as a flying-spot scanner.
These conventional automatic postal-code-number reading systems are practicle only to sort mail which has strictly preassigned area for the postal code number. Recently, however, a need has arisen for adaptation to more flexibly preassigned areas for postal code on mail items, particularly bulk mail items.
In the conventional automatic postal-code-number reading system adapted to handle such mail items, the entire area for the postal code must be scanned by the scanning means, and the scanning output must be stored in storing means to recognize the postal code. As a result, a large capacity is needed for the storing means. This tends to slow down the handling speed.